An ESP32-S3 board for vending machines with RS485, microSD card slot, optional cellular mPCIe module

LILYGO T-Vending is an ESP32-S3 WiFi and Bluetooth IoT board designed for vending machines with an RS485 terminal block, a microSD card slot, and support for an optional cellular mPCIe module.

As I understand the board is connected to the vending machine through the RS485 terminal block to control vend motors (potentially via an additional board to control multiple motors) and a 10-pin connector for power (12V/24V), signals to/from a coin mechanism and other parts. The board also adds a Grove connector and an unpopulated 12-pin GPIO header for expansion.

T-Vending specifications:

ESP32-S3-WROOM-1 wireless module
- SoC – ESP32-S3FN16R8 dual-core Tensilica LX7 microcontroller @ up to 240 MHz with
  - 2.4 GHz 802.11n WiFi 4 and Bluetooth 5.0 LE connectivity
  - Memory – 8MB PSRAM
  - Storage – 16MB SPI flash
- PCB antenna
Storage – MicroSD card slot
Wireless
- 2.4 GHz 802.11n WiFi 4 and Bluetooth 5.0 LE connectivity (ESP32-S3)
- Optional T-PCIe 4G LTE cellular module (e.g based on SIM7600) via mPCIe socket and micro SIM card slot
Serial
- RS485 A/B terminal block
- Isolation voltage: 3,000V; isolation output: 5V/50mA (0.25W)
- Communication rate: 1200 to 1,280,000 bps
USB – 1x USB Type-C port for programming, 4-pin header for “Modem” USB 2.0 interface
Expansion
- 4-pin Grove connector (UART)
- 12-pin GPIO header with 10x GPIOs, 3.3V, and GND
- 10-pin 2.0mm pitch connector with UART, PULSE, GPIOs, GND, 12/24V DC input
Misc – Reset and Boot button
Power Supply – 12-24V DC via 10-pin connector
Dimensions – 102 x 46 x 12.5mm

Adding a cellular module would completely cover the ESP32-S3 module including the PCB antenna, so it’s unclear what effect it may have on the WiFi and Bluetooth signals. As usual, LILYGO provides the PDF schematic and some Arduino code samples on GitHub. Those include the factory test tool, RS485 Master/Slave samples, an SPI sketch, and as a “Wire” program showing how to use I2C.

Since an ESP32-S3 board for vending machines is a rather niche product, I wish LILYGO had a complete example project, but I could not find any, so users will need to find by themselves how to integrate the board into a vending machine, and write the program from scratch. The board does come with a 10-pin cable with jumper wires for easier connection, a 12-pin GPIO header, and screws to secure the optional cellular module.

LILYGO sells the T-Vending board on Aliexpress for $23.38 including shipping. If you need a cellular connection, you can buy one of the T-PCIe modules such as the SIM7600 models that go for $36 to $51 depending on the selected region.

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.